Fluff suppression apparatus

Abstract: A fluff suppression apparatus (1) comprising a pair of rollers (11,12) disposed with axes of rotation thereof crossed with each other and in contact with each other for nipping and sending out a yarn (Y), and at least one of the pair of rollers has, at a contacting portion thereof with the yarn, has resiliency and flexibility and has a cavity formed in the inside thereof.

Description: Background of the Invention Field of the Invention This invention relates to a fluff suppression-apparatus which is a working apparatus for a spun yarn. Prior Art Conventionally, in a pneumatic spinning machine, a sliver supplied from a can is first drafted by a drafting apparatus, which is formed from three or more pairs of draft rollers, and is then passed through a pneumatic spinning nozzle, in which whirling air flows by jetting of compressed air are produced, to temporarily twist and spin the same to produce a spun yarn which is in a twisted condition as twined fibers are present- on the surface layer of parallel core fibers. On the surface of such a spun yarn, extremities of part of the twined fibers are separated to form much fluff, which makes the spun yarn a cloudy yarn, having a significant influence on the quality of the spun yarn. Thus, a fluff suppression apparatus has been developed and is disclosed in DE-A-42 39 310 comprising a pair of rotary members disposed with axes of rotation thereof crossed with each other and in contact with each other for nipping and sending out a yarn and at least one of said pair of rotary members has, at a contacting portion thereof with a yarn, soft resiliency. This contacting portion is formed by a rubber covering. Such a fluff suppression apparatus, however, has a problem in that at least the rotary member having the rubber covering is liable to be locally abraded at a location thereof at which a yarn is nipped and besides an operation for maintenance such as adjustment of the contacting pressure is not easy. Summary of the Invention It is an object of the present invention to provide, in view of such points of the prior art a s described above, a fluff suppression apparatus which can produce a spun yarn substantially free from fluff and is superior in durability and easy to perform maintenance such as adjustment of the contacting pressure. The invention thus provides a fluff suppression apparatus of the present invention is contructed such that it comprises a pair of rotary members disposed with axes of rotation thereof crossed with each other and in contact with each other for nipping and sending out a yarn, and at least one of the pair of rotary members has, at a contacting portion thereof with the yarn, soft resiliency and a cavity formed in the the inside thereof The contact between the two rotary members is face contact and a yarn is nipped with certainty so that a spun yarn substantially free from fluff can be obtained, and besides, since adjustment of the contacting pressure is easy, the structure for the driving transmission can be simplified. Further, since face contact is involved, a traverse system can be adopted, and consequently, local abrasion of the rotary members can be prevented and the durability of the apparatus can be enhanced. The contacting pressure, that is, the contacting depth of the one roller having resiliency and flexibility with the other roller is held fixed as an allowable range is produced to some degree by deformation of the one roller upon pressure contact, and adjustment of the contacting pressure is easy. Further, since the rollers contact in face contact with each other and also the contacting pressure distribution in the contacting plane is comparatively uniform, a yarn can be traversed within the contacting plane, and in this instance, local abrasion of the rollers is prevented. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a spinning apparatus which employs a fluff suppression apparatus of an embodiment of the present invention; FIG. 2 is a perspective view, partly in section, showing the fluff suppression apparatus of the embodiment of the present invention; FIG. 3 is a side side elevational sectional view showing the fluff suppression apparatus of the embodiment of the present invention; FIG. 4 is a plan view showing the fluff suppression apparatus of the embodiment of the present invention; FIG. 5 is a graph illustrating the relationship between the circumferential speed of an upper roller and the amount of fluff; FIG. 6 is a graph illustrating the relationship among the circumferential speed of the upper roller, the circumferential speed of a lower roller and the tension of a yarn; and FIG. 7 is a graph illustrating the relationship between the position of a yarn guide and the amount of fluff. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT An embodiment will be described with reference to the drawings. A spinning apparatus 100 which employs a fluff suppression apparatus 1 of the present invention is shown in FIG. 1. Referring to FIG. 1, the spinning apparatus 100 includes a drafting apparatus 130 of the four lines type including a back roller pair 130a, a third roller pair 130b, a second roller pair 130c on which a pair of apron belts 130a are mounted, and a front roller pair 130d, a pneumatic spinning apparatus 140 wherein two pneumatic spinning nozzles of a first nozzle and a second nozzle in each of which a pair of compressed air jetting nozzles for producing whirling air flows in the opposite directions to each other are opened to the inside are arranged in series, a delivery roller 2, the fluff suppression apparatus 1, a slack tube 170, a yarn clearer 180 having a yarn defect detection function and a fluff amount measurement function, and a take-up apparatus 190, all arranged in order from the upstream side to the downstream side. The spinning apparatus 100 is constructed such that a sliver S supplied from a can 120 is first drafted by the drafting apparatus 130 and then twisted by false twisting by the pneumatic spinning apparatus 140 to spin a spun yarn and then the spun yarn delivered from the delivery roller 2 is passed through the fluff suppression apparatus 1 to make a spun yarn Y whose fluff is suppressed, whereafter the spun yarn Y is taken up onto a package P by the take-up apparatus 190 in which it is traversed by a traverse guide 190a while a friction roller 190b which rotates positively is contacted under pressure with the package P. A unit is made up of the spinning apparatus 100 as shown in FIG. 1 and a single spinning frame is constituted of a plurality of the units which are arranged in parallel. Referring to FIGS. 2 to 4, the fluff suppression apparatus 1 of the present embodiment is principally constituted from a lower roller 11 and an upper roller 12 having an axis of rotation crossing with that of the lower roller 11 and contacting with the lower roller 11 such that a yarn is nipped between and sent out by them. In the embodiment shown, the fluff suppression apparatus 1 is provided on the downstream side of the deliver roller 2 of the spinning machine. The lower roller 11 is in the form of a metal roller processed by processing for increasing the coefficient of friction such as forming, on the surface thereof, as shown in FIG. 4, lines (threads) 11a of the pitch of approximately 0.3 mm and the depth of approximatley 0.5 mm in a direction perpendicular to the axial line by thread cutting or a like operation, and such lower rollers 11 are secured to a drive shaft 13 which is provided to extend across a large number of spindles arranged in a juxtaposed relationship in the spinning machine so that they are driven all together. As such processing for increasing the coefficient of friction, blast processing or like processing may be applied to the surface of the metal. The lower roller 11 may also be in the form of a rubber roller, but from the point of view of durability, preferably it is in the form of a metal roller. The upper roller 12 is a hollow and cylindrical rubber roller of a thin material as shown in FIG. 3 and is processed by crowning so that a central portion thereof has a larger diameter than the opposite end portions 12a and 12b thereof. And, the upper roller 12 is supported on a roller core member 15 while prevented from being pulled off from the roller core member 15 by fitting the opposite end portions 12a and 12b thereof onto the opposite end flange portions 15a and 15b of the roller core body 15 fitted on a rotary shaft 14 and then securing a disk 17 to an end of the rotary shaft 14 by means of a screw 16. It is to be noted that the cavity in the inside is not completely closed up, and accordingly, if the roller 12 is pressurized from the outside, then it is depressed readily. That is , an atmospheric pressure in the inside of the cavity is maintained under general atmosphere. Furthermore, the cavity within the roller 12 is continuous to the outside of the roller 12, so that the heat stored within the cavity of the roller can be dispersed to the atmosphere. The rotary shaft 14 is supported for rotation by means of a bearing 19 at one of a pair of ends of a bifurcated bracket 18 secured to a machine frame 3 by means of a pair of bolts 4 and 5, and is disposed obliquely at an angle  (for example, 15°) within a horizontal plane with respect to a yarn delivering direction. And, a pulley 20 is secured to the other end of the rotary shaft 14. A round belt 25 extends between the pulley 20 and four pulleys 21, 22, 23 and 24 supported for individual rotation on the bracket 18, and the round belt 25 is contacted, on an outer periphery side thereof between the pulley 22 and the pulley 23, under pressure with the drive shaft 13 for the lower roller 11. Meanwhile, a threaded hole 6 for one 5 of the bolts 4 and 5 for securing the bracket 18 to the machine frame 3 is in the form of an arcuate elongated hole centered at a threaded hole for the other bolt 4 so that the mounting angle of of the bracket 18 can be varied in a vertical direction with respect to the bolt 4. The mounting angle is set so that the contacting pressure of the round belt 25 with the drive shaft 13 may be an appropriate value, and the bracket 18 is secured at the position. And, a yarn guide member 26 is provided on the yarn introduction side of the fluff suppression apparatus 1. The yarn guide member 26 is formed from a wire material which is bent so as to provide a yarn guide portion 26a substantially at a central portion thereof, and the yarn guide portion 26a supports a spun yarn Y in the rightward direction in FIGS. 2 and 4 thereon to prevent the spun yarn Y from being fed in a driving direction 12a of the upper roller 12 and guides the spun yarn Y to a contacting plane T between the lower roller 11 and the upper roller 12 which will be hereinafter described. Meanwhile, a terminal end side of the yarn guide member 26 with respect to the yarn guide portion 26a is formed in an arc along the circumference of the upper roller 12 to form a yarn introduction guide member 27, and when the spun yarn Y is to be introduced into the fluff suppression apparatus 1, the spun yarn Y is guided by the yarn introduction guide member 27 so that it can be introduced into the contacting plane T between the upper roller 12 and the lower roller 11. The yarn guide member 26 is secured at a base portion thereof to a traverse member 28, which is moved back and forth in the direction of an arrow mark 28A in FIG. 4 by a power source not shown. Subsequently, action will be described based on the embodiment. Rotation of the drive shaft 13 for the lower roller 11 is transmitted to the rotary shaft 14 for the upper roller 12 by way of the round belt 25 and the pulley 20 so that the upper roller 12 is driven in the direction of the arrow mark 12A in the contacting plane T at a fixed ratio in speed to the lower roller 11. Since the upper roller 12 has a larger diameter at the central portion than the opposite end portions 12a and 12b thereof and the surface of the roller 12 has an arch-like shape convex toward the outside from the axis of the roller 12 as described hereinabove, the roller 12 yields so-called "resiliency" so that a strong contacting pressure can be obtained when the lower roller 11 is contacted under pressure with the upper roller 12. Consequently, the hollow upper roller 12 made of rubber and having a small material thickness is further swollen by a centrifugal force acting upon the upper roller 12 so that, at the contacting portion thereof with the lower roller 11, it is pressed further strongly against the circumference of the lower roller 11 and besides it is deformed along the profile of the lower roller 11 as shown in FIG. 3, and as a result, the contacting plane T provides face contact over a comparatively wide area as shown in FIG. 4. Consequently, since an allowable range to some degree is produced in the depth of contact of the upper roller 12 with the lower roller 11, adjustment of the contacting pressure is easy, and it is possible, as in the present embodiment, to support the pulleys 22 and 23 and the upper roller 12, on which the round belt 25 for driving transmission is supported, by means of the common bracket 18 and perform mounting of the bracket 18 placing the precedence on setting of the contacting pressure of the round belt 25 with the drive shaft 13. And, the spun yarn Y spun by the spinning apparatus not shown and delivered from the delivery roller 2 is guided by the yarn guide member 26 and sent into the contacting plane T, and then when it is nipped between and sent out by the lower roller 11 and the upper roller 12, which contacts with the lower roller 11 with its feeding direction crossing with that of the lower roller 11, a false twisting action and a rubbing action are applied to the spun yarn Y. Consequently, fluff on the surface of the spun yarn Y is pressed to the yarn itself and suppressed. Meanwhile, since the lower roller 11 and the upper roller 12 contact in face contact with each other over a comparatively wide area as described above, the spun yarn Y can be traversed within the contacting plane T by moving the yarn guide member 26 back and forth by means of the traverse member 28. Consequently, also where a rubber roller is employed for the lower roller 11, local abrasion at the nipping portion of the lower roller 11 can be prevented and the durability of the lower roller 11 can be enhanced. A yarn can be easily introduced between the lower roller 11 and the upper roller 12 since the rollers 11 and 12 are contacted with each other at the curved surfaces thereof. Furthermore, the contacting pressure between the rollers 11 and 12 may be maintained to be constant being regardless of mechanical vibration because the contacting area of the rollers with a yarn is constituted by using soft resilient material, that is, the hollow roller 12 made of rubber. To accomplish an appropriate soft resilient condition, it is preferred to use the hollow roller 12 made of rubber having 70 to 90 degree in hardness, preferable 75 to 80 degree in hardness and having thickness (thickness at an central portion of a roller) being 1 to 2.5 mm, preferable 1.6 to 2.0 mm. In the following, the degree of suppression of fluff will be described based on concrete experimental data. FIG. 5 is a graph illustrating the relationship between the circumferential speed of the upper roller and the amount of fluff when a blended yarn of Ne of 30 made of polyester of 65% and cotton of 35% was spun under the spinning conditions of the spinning speed of 212 m/min and the feed rate of 0.97 and, in the fluff suppression apparatus 1 shown in FIGS. 2 to 4, the hollow upper roller made of rubber and having the thickness of 2 mm was contacted under pressure with the contacting depth of about 1 mm with the lower roller made of sintered stainless steel and having longitudinal lines at the pitch of 0.4 mm to apply fluff suppression to the blended yarn. The amount of fluff is a total number of fluff pieces observed at the position spaced by 0.5 mm from the center of the yarn per 10 m in length of the spun yarn. Meanwhile, FIG. 6 is a graph illustrating the relationship among the circumferential speed of the upper roller, the circumferential speed of the lower roller upon the measurement of the amount of fluff described above and the tension of the spun yarn upon introduction of the yarn into the fluff suppression apparatus 1, and the circumferential speed ratio between the circumferential speed of the upper roller and the circumferential speed of the lower roller is kept fixed at about 1:1.3. From FIG. 5, it can be seen that the amount of fluff of the spun yarn to which fluff suppression was applied by the fluff suppression apparatus 1 is reduced to substantially 4 to 8% of the number of fluff pieces of 3,450 of another spun yarn which was spun in the same conditions but was not processed by fluff suppression, and the spun yarn is substantially in a fluff-free condition and the fluff exhibits a tendency that it further decreases as the circumferential speed of the upper roller increases. Meanwhile, FIG. 7 is a graph illustrating the relationship between the yarn guide position d and the amount of fluff in the fluff suppression apparatus 1 wherein the circumferential speed of the lower roller was set to 15 m/min and the circumferential speed of the upper roller was set to 288 m/min (circumferential speed ratio 1:1.92) for a similar spun yarn spun at the spinning speed of 150 m/min. The yarn guide position d is the amount of displacement of the yarn guide portion 26a of the yarn guide member 26 from a yarn delivering line 2c of the delivery roller 2 shown in FIG. 4, and is positive in the rightward direction in FIG. 4. FIG. 7 indicates that, while the quantity of fluff is in a tendency that it decreases a little as the yarn guide position d is displaced to the right side and the nipping point in the contacting plane T shown in FIG. 4 moves to the right, when the yarn guide position d is within the range of 3 to 20 mm, the fluff suppression condition is substantially fixed, and it is possible to traverse the yarn within that range. While, in the embodiment described above, a solid roller is employed as the lower roller, a hollow rubber roller similar to the upper roller may be employed, or a roller formed in a balloon shape may be used for the hollow roller and have compressed air enclosed therein to obtain a certain contacting pressure. Further, a porous resilient member such as sponge may be employed in place of a rubber roller.

Claims: A fluff suppression apparatus, comprising a pair of rotary members (11, 12) disposed with axes of rotation thereof crossed with each other and in contact with each other for nipping and sending out a yarn (Y), wherein at least one (12) of said pair of rotary members (11, 12) has, at a contacting portion thereof with the yarn (Y), soft resiliency, and wherein the rotary member (12) which has soft resiliency is formed at the surface thereof from a soft resilient member, and has a cavity in the inside characterized in that the rotary member (12) which has soft resiliency is a hollow rubber roller. A fluff suppression apparatus, comprising a pair of rotary members (11, 12) disposed with axes of rotation thereof crossed with each other and in contact with each other for nipping and sending out a yarn (Y), wherein at least one (12) of said pair of rotary members (11, 12) has, at a contacting portion thereof with the yarn (Y), soft resiliency, and wherein the rotary member (12) which has soft resiliency is formed at the surface thereof from a soft resilient member, and has a cavity in the inside characterized in that the rotary member (12) which has soft resiliency is made of a porous resilient material. A fluff suppression apparatus as claimed in claim 1 or 2, wherein one (12) of said rotary members (11, 12) is a roller having soft resiliency, and the other rotary member (11) is a roller made of a metal. A fluff suppression apparatus as claimed in claim 3, wherein the surface of the roller (11) made of a metal is processed by processing for increasing the coefficient of friction thereof. A fluff suppression apparatus as claimed in one of claims 1 to 4, wherein said pair of rotary member (11, 12) are disposed with the axes of rotation thereof crossed substantially perpendicularly with each other. A fluff suppression apparatus as claimed in one of claims 1 to 5, wherein one of said rotary members (11, 12) is formed in an arch-shape such that a central portion thereof has a larger diameter than the opposite end portions (12a, 12b) thereof, and the central portion of the larger diameter contacts with the other rotary member (11). A fluff suppression apparatus as claimed in one of claims 1 to 6, further comprising a yarn guide member (26) for controlling the path of the yarn (Y). A fluff suppression apparatus as claimed in claim 7, wherein said yarn guide member (26) moves back and forth in parallel to the axis of the other rotary member (11) to traverse the yarn (Y). A fluff suppression apparatus as claimed in one of claims 1 to 8, wherein said fluff suppression apparatus is disposed on the downstream side of a delivery roller (2) of a spinning apparatus (100) in which a drafting apparatus (130), a pneumatic spinning nozzle (140), said delivery roller (2) and a take-up apparatus (190) are installed in order, and applies twisting and rubbing to a spun yarn (Y) having passed said deliver roller (2) to reform the spun yarn (Y). A fluff suppression apparatus as claimed in one of claims 1 to 9, wherein a pair of said rotary members (11, 12) are contacted with each other at the curved surfaces thereof, respectively. A fluff suppression apparatus as claimed in claim 1, wherein both of the paired rotary members (11, 12) are hollow rollers made of rubber. A fluff suppression apparatus as claimed in claim 1, wherein said hollow roller (12) is made of rubber having 70 to 90 degree in hardness and having thickness being in the range of 1 to 2.5 mm.

Inventors: MARUKI HIROSHIGE, MEKATA TSUTOMU, MARUKI, HIROSHIGE, MEKATA, TSUTOMU
Applicants: MURATA MACHINERY LTD, MURATA KIKAI KABUSHIKI KAISHA
Application year: 1994
Main classification: D01H1
IPC codes: D01H1, D01H13, D01H11, D01H5, D02J3